The general aim has been to determine for patients with osteosarcoma which characteristics, if any, of patient, tumor, calendar time and treatment are predictive of survival from initial treatment, to metastasis, to death. Specifically, however, this project investigates osteosarcoma in response to controversy about the diagnosis and treatment of this disease. It is multi-institutional not only to get enough cases but also to compare cases, treatment and survival among a group of 14 institutions. One of these institutions claims that treatment by surgery alone is associated with recent dramatic improvement in survival. It uses little chemotherapy. All the others use chemotherapy extensively along with surgery. A randomized clinical trial is called for here but is, practically speaking, impossible to accomplish. (Only one randomized trial has been done; it was inadequate in size but it seemed to show no difference between surgery with Methotrexate and surgery without.) This study simulates such a trial by (1) abstracting data uniformly using 3 or 4 trained abstractors visiting all institutions, (2) reviewing at one pathology center the diagnostic slides and x-rays from all institutions, (3) subjecting the data to the full power of modern statistical methods for the survival analysis. While not perfect, the comparisons made by skillful use of multiple regression (Cox method and others) are expected to elucidate important aspects of this disease. The last eligible case occurred late in 1982. We need time for follow-up, a minimum of two years after diagnosis. The institutions need time to find these patients and get the follow-up data. The study needs time to query the institutions to do a uniform abstracting of follow-up data and get that information into the computer. Then the final analysis can be completed.